Development of RF MEMS switch on flexible organic substrate with wafer transfer technology (WTT)

This paper demonstrates, for the first time, the fabrication of RF MEMS switches on a flexible organic substrate (FR-4) using wafer transfer technology (WTT). The switches were first fabricated on a low resistivity silicon wafer using a standard MEMS process. Eventually these switches were transferred onto a FR-4 substrate by bonding followed by mechanical grinding and wet removal of silicon. The RF MEMS switches with flat metal bridge (top electrode) and precisely controlled gap between the bridge and bottom electrode demonstrated a low insertion loss (less than 0.15dB at 20GHz) and high isolation (21dB at 20GHz). This technology indicates the potential to integrate RF MEMS components with other RF devices on the same organic substrate for implementation of compact RF system